A simple checkbox to turn off the computer after backup finishes
successfully. It is off by default and must be switched on every time
(unexpected system shutdowns are a huge pain, much more problematic
than forgetting to shut down can be).
fixesQubesOS/qubes-issues#2039
Partial fix - the progress bars now move, although they do not really
indicate progress (just dance back and forth). Future fix would include
making a tray icon to signal backup progress instead.
Initial restoration: basic backup-and-restore works, but
- progress bar in backup does not work
- selecting only some VMs to restore does not work
- various miscellaneous enhancements are not yet in place
